Generally, cooling of beverage contained in a container such as a bottle, can, pet bottle is accomplished by storing in a cooling apparatus such as a refrigerator. But in summer it takes long time to cool the beverage.
The prior art of using a freon gas has a problem of destruction of ozone layer.
Korean Patent Registration No. 240,195 discloses a prior art of the invention. The prior art discloses a portable cooling device comprising a coolant gas bottle for storing a coolant gas, a coolant gas rod for emitting the coolant gas stored in the coolant gas bottle, a cap coupled to a top of the coolant gas rod and a coolant gas bottle case for protecting the coolant gas bottle. It is portable but can not be applied into an airtight container such as a can.
Further, Korean Patent Registration No. 240,197 discloses a prior art of the invention. The prior art discloses a beverage can having an internal cooling means. The internal cooling means is provided with an upper surface member and a bottom surface member with interval, a sponge is inserted between the upper and bottom surface member and the coolant gas is absorbed into the sponge through the bottom surface member thereby preventing an accident of explosion. As the coolant gas is stored in the bottom of the can, the beverage in the can is not able to be proportionally entirely cooled and the internal capacity of the can is reduced.